The application of fertilizers, weedkillers, fungicides and pesticides is vital to the enchancement of crop growth and to the operation of systems of weed and pest control. Where this application is by mechanical sprayer, it is most common that the apparatus used will comprise a very long thin boom-supported centrally hinged metal pipe which, when in operation, is parallel to the ground surface and is attached to a tank containing liquid, itself either mounted on, or towed by, a tractor.
The liquid is sprayed through apertures or nozzles situated in the underneath of the pipe. Although a cloud of droplets trails the apparatus during operation in such a way that the application may be considered to be thorough, the usefulness of the above-described apparatus is limited due to the fact that the point of application is near to ground level and thus it is impractical to use the above described apparatus in the treatment of tall crops and trees. Indeed, at the present time the most thorough method of spraying trees is by manual application with a hand held spray; this method is obviously very costly in man-hours.